Guillain-Barré syndrome (GBS) is the most common cause of acute paralysis and neuromuscular ventilatory failure. Although treatment with plasma exchange and immune globulins has decreased the duration of mechanical ventilation by half, 10% to 30% of patients require mechanical ventilation, 5% to 10% remain seriously disabled, and 3% to 8% die as a result of largely avoidable complications. Good clinical outcome depends to a large extent on the anticipation and management of ventilatory failure and its complications.